| 초록 |
Nanomechanical thermal analysis (NTA) was used to study the glass transition behaviors of Poly(styrene-b-methyl methacrylate). A few nanogram samples of Poly(styrene-b-methyl methacrylate) with different molecular weight ratio were coated onto the one side of silicon microcantilevers, and the variations with temperature in the deflection, Q factor and resonant frequency of the cantilevers were measured simultaneously. The changes in the resonance frequency and the inverse of the Q factor of the cantilever are related to the variations in the elastic modulus and the loss tangent of Poly(styrene-b-methyl methacrylate), respectively. The difference between the volume expansion coefficients of Poly(styrene-b-methyl methacrylate) and silicon induced the cantilever to bend, and this variation was used to determine the glass transition temperature as well as the physical properties of the Poly(styrene-b-methyl methacrylate) sample. |
